👔 contains-duplicate solution

Author: dohee789

contains-duplicate/dohee789.java

@@ -0,0 +1,15 @@
+/*
+https://leetcode.com/problems/contains-duplicate/
+ */
+class Solution {
+    public boolean containsDuplicate(int[] nums) {
+        Set<Integer> set = new HashSet();
+        for(int n: nums){
+            if(set.contains(n)){
+                return true;
+            }
+            set.add(n);
+        }
+        return false;
+    }
+}